PHP | xml_set_character_data_handler() Function

The xml_set_character_data_handler() function is an inbuilt function in PHP which is used to set the character data handler function for XML parser.

Syntax:

bool xml_set_character_data_handler( resource $xml_parser, callable $data_handler )

Parameters: This function accepts two parameters as mentioned above and described below:  

• $xml_parser: It is required parameter. It holds the reference of XML parser to set up character data handler.
• $data_handler: It is required parameter. It is a string which contains the name of function. 

handler( resource $parser, string $data )

The handler function must have these two parameters: 

• $xml_parser: It holds the reference of XML parser which is calling to handler.
• $data: It holds the character data as a string.

Return Value: This function returns True on success or False on failure.

Note:

• This function is available for PHP 4.0.0 and newer version.
• These examples may not work on online IDE. So, try to run it on local server or php hosted servers.

gfg.xml file:

XML

<?xml version="1.0" encoding="utf-8"?>
<user>
    <username> user123 </username>
    <name> firstname lastname </name>
    <phone> +91-9876543210 </phone>
    <detail> I am John Doe. Live in Kolkata, India. </detail>
</user>

Program 1:

PHP

<?php

// Create an XML parser
$xml_parser = xml_parser_create();

// Set the character handler function for XML parser
xml_set_character_data_handler($xml_parser, "char_print");

// Opening xml file
$file_pointer = fopen("gfg.xml", "r");

// Reading xml data from file
while($data = fread($file_pointer, 4096)) {

    // Parsing XML data
    xml_parse($xml_parser, $data, feof($file_pointer)) or

    // Display error when parsing error occurs
    die (sprintf("XML Error: %s at line %d",

        // Error string
        xml_error_string(xml_get_error_code($xml_parser)),

        // Current line
        xml_get_current_line_number($xml_parser)));
}

// Free to xml parser
xml_parser_free($xml_parser);

fclose($file_pointer);

// Character handler function for XML parser
function char_print($xml_parser, $data_to_print) {
    echo $data_to_print;
}

?>

Output:

user123 
firstname lastname 
+91-9876543210 
I am John Doe. Live in Kolkata, India. 

Program 2:

PHP

<?php

// Create an xml parser
$xml_parser = xml_parser_create();

// Element handler function named "starting_handler"
// enables custom manipulation for output
function starting_handler($xml_parser,
            $element_name, $element_attrs) {

    switch($element_name) {
        case "USER":
            echo "<u>USER DATA</u><br>";
            break;
        case "USERNAME":
            echo "Username: ";
            break;
        case "NAME":
            echo "Name: ";
            break;
        case "PHONE":
            echo "Phone no: ";
            break;
        case "DETAIL":
            echo "More about user: ";
    }
}

// Element handler function named "ending_handler"
function ending_handler($xml_parser, $element_name) {
    echo "<br>";
}

// Character handler function named "char_handler"
function char_handler($xml_parser, $data) {
    echo $data;
}

// Setting element handlers
xml_set_element_handler($xml_parser,
        "starting_handler", "ending_handler");

// Setting character data handler
xml_set_character_data_handler($xml_parser, "char_handler");

// Opening xml file
$file_pointer = fopen("gfg.xml", "r");

// Reading xml file
while ($data = fread($file_pointer, 4096)) {
    xml_parse($xml_parser, $data, feof($file_pointer)) or

    // Display error while xml parsing
    die (sprintf("XML Error: %s at line %d",

        // Error string
        xml_error_string(xml_get_error_code($xml_parser)),

        // Error line number
        xml_get_current_line_number($xml_parser)));
}

// Free to xml parser
xml_parser_free($xml_parser);

// Closing file stream
fclose($file_pointer);

?>

Output:

USER DATA
Username: user123
Name: firstname lastname
Phone no: +91-9876543210
More about user: I am John Doe. Live in Kolkata, India.

Reference: https://www.php.net/manual/en/function.xml-set-character-data-handler.php